1. Field of the Invention
The present invention relates to a method and apparatus for radio propagation modeling, and more particularly, to a method and apparatus for radio propagation modeling which can minimize an error due to a shade area generated when a wall having a thickness is processed as a line having no thickness, for easy and quick calculation, in a ray-tracing propagation model.
The present invention was supported by the Information Technology (IT) Research & Development (R&D) program of the Ministry of Information and Communication (MIC) and the Institute for Information Technology Advancement (IITA), Republic of Korea. [Project No. 2005-5-046-03, Project Title: Development of the basic spectrum resource utilizing technology].
2. Description of the Related Art
A method of predicting and modeling radio propagation includes a statistic method using measurement results in a wide range and a theoretical approach method. A ray-tracing method belongs to the theoretical approach method and can predict radio propagation more accurately than other methods. This method needs too long of a calculation time for prediction and thus has not used much in the past. However, with the recent development in computing capacity and continuous studies thereon, the calculation time in a limited area can be much reduced.
When radio propagation is modeled using a ray-tracing method, a shade area is generated by a wall or obstacle. In the shade area, there is no path through which a radio wave can directly propagate and propagation loss is great due to diffraction or diffusion.
When radio propagation is predicted using the ray-tracing method, a reflection object or obstacle located on a propagation path is mathematically represented as simple as possible to reduce the amount of calculations. In particular, for a wall, the thickness of the wall is omitted and the complexity of calculations is avoided by processing a two-dimensional wall as a line and a tree-dimensional wall as a surface. However, such simplification results in an area, corresponding to an actual shade area, be represented as an area that is not the shade area, and thus, an error of the propagation loss according thereto cannot be neglected.
To address the above problem, according to conventional technology, the difference from the actual case is neglected so that a calculation speed is increased while sacrificing accuracy. In contrast, even though accuracy is not sacrificed by considering the thickness of a wall, the calculation speed is decreased.